Transaction Control call in RICO process?

An RICO (Requester Initiated Change Order) process is as follows -

1. Raise a Project Requisition. Approve the Requisition.

2. Convert the Requisition to a PO

3. Go to the Requisition raised per step #1. Go for the RICO. Say, try changing any fields of the Requisition or change Dollar Amount, etc.

The query is - is the Transaction Control is called during the RICO process?

Per our testing, we are not seeing the Transaction Control being called. We have built some custom logic in the extension and this we see is not being executed..